High temperature and high pressure reactions require a reactor adapted to handle such conditions. Reactions, such as the devulcanization of rubber or mineral extraction, are examples of high temperature high pressure reactions. Rubber can be devulcanized by heating it to between 250° C. and 350° C. in an aqueous solution for about one hour with pressures up to about 1500 psi as described in Canadian patent application 2,441,713 which is incorporated herein. The rubber pieces are usually relatively large as smaller pieces tend to agglomerate and become sticky when processed. Because of this, a batch type of reactor is required. The reactor required to contain the high temperatures and pressures involved is very heavy and has a very large thermal mass and therefore requires a substantial amount of heat energy to raise the temperature of the reactor up to a reaction temperature. Current reactors and reactor systems require many hours of heating to heat a reactor full of liquid up to temperature and then cool it down and are therefore not very commercially practical. Additionally, reheating of a reactor after cool-down requires a large amount of heat energy as the outer reactor wall of a high pressure reactor has a very large thermal mass.
Furthermore, heating a large reactor from the outside that is full of liquid and a material to be processed, such as rubber or in a mineral extraction from rocks or the like (that is a poor thermal conductor), also results in large temperature gradients within the reactor.
Additionally, much of the heat energy required to increase the temperature of the reactor or reactants and/or solvent to a processing temperature is lost when the reaction is complete and the reactor is cooled for removal of the reaction product.
There is therefore a need for a reactor whereby the reactant can be rapidly and evenly heated to the processing temperature, held there for a desired time period and then rapidly cooled.